Mounted variables not showing in next files (Vue.js)

Question

Hello, I have this code in my Vue3 App.

main.js:

import App from './App.vue';

const app = createApp({
              data: () => {
                return {
                  message: "Hello";
                }
              },
              render: () => (
                h(App);
              )
            });

But app when mounted write me this error when i using {{ message }} in views/Home.vue

Property "message" was accessed during render but is not defined on instance.

How fix thats?